1. Field of the Invention
The invention relates to a conveyor roller and to a conveyor path comprising such a conveyor roller.
2. Description of the Related Art
Roller conveyors with rollers exist in the prior art. These roller conveyors are used, for example, in rack storage systems, wherein a rack can have a plurality of roller conveyors arranged above and alongside one another. A plurality of pallets with goods can be mounted one behind the other on a roller conveyor, these pallets being conveyed on the rollers.
The roller conveyors are generally loaded from one side and unloaded from the other side, so that the goods that pass onto the roller conveyors first are also unloaded again first therefrom. These rack storage systems are called first-in/first-out storage systems or FIFO storage systems. The conveyor paths of these FIFO conveyors may be arranged horizontally or may have an inclination which slopes from the loading point to the unloading point. In case of a horizontal conveyor path the conveyor may include driven rollers for accelerating and or retarding the goods on the conveyor path. In case of an inclined conveyor path pallets located on the conveyor path can be conveyed in the direction of the unloading point by gravitational force. Also in this case rollers including a drive or a brake may be provided.
Alternatively, the roller conveyors are loaded from one side and unloaded from the same side, so that the goods that pass onto the roller conveyors last are unloaded first therefrom. These rack storage systems are called last-in/first-out storage systems or LIFO storage systems. Some of these storage systems also have an inclination in the direction of the loading or unloading point. When loading a further new pallet, for example by means of a forklift truck, the pallets that are already located on the roller conveyor are pushed rearward by the new pallet counter to the inclination. Moreover, this inclination has the effect that the pallets located on the roller conveyor always line up at the unloading point following gravitational force.
In order to brake the speed of the pallets in the LIFO roller conveyors, also the rollers of the LIFO conveyors can in part be provided with brakes via which the speed of the rollers, and hence that of the pallets, can be retarded. It can thereby be prevented that the pallets run against one another at excessively high speed.
In some constructions, eddy-current brakes are used for this. Such a device for braking individual rollers of roller tracks is described in DE 7300091 U. A further construction is described in EP 1 243 528 A1.
A torque generated inside the rollers for accelerating the goods positively or negatively has to be transmitted to the frame of the conveyor.
Accordingly, rollers including a brake or an electrical motor need to be attached to a frame such that a torque generated within the roller can be transmitted or absorbed, in the frame of the conveyor.
It is an object of the invention to provide a compact conveyor roller and a conveyor path comprising at least one such conveyor roller, wherein conveyor rollers can be produced and mounted in the conveyor path in a cost-effective manner, wherein the conveyor rollers have a long service life and also have low maintenance and/or repair costs during their service life.